Research is proposed to study, in longitudinal samples, changes in the visual response of human infants to contour and configuration over the first several months of life, with special attention to the course of temporal integration. Four groups of studies will investigate the following issues: 1) How varying levels of contrast and luminance affect the infant's response to edges; 2) What the temporal and spatial characteristics of the infant's developing response to peripheral stimulation are; 3) How the infant deals with visual stimuli presented as components over time; and 4) How age and specific visual experience in the first days of life affect the infant's responses to intensity, hue, and configuration. In all studies, three developmentally different groups of infants will be observed longitudinally: normal term, premature normal-weight-for-dates, and light-for-dates babies. Using the corneal reflection techniques and several derived measures of vision, the early development of the relation between looking-time measures and ocular orientation measures of the child's response to contour and figure will be studied. The developmental course of observed relations among components of visual response and capacities for temporal integration may help illuminate the specific precursors and nature of cognititve deficits observed in some premature and light-for-dates infants.